Synaptic zinc contributes to motor and cognitive deficits in 6-hydroxydopamine mouse models of Parkinson’s disease Joanna Sikora, Brigitte Kieffer, Pierre Paoletti, Abdel-Mouttalib Ouagazzal To cite this version: Joanna Sikora, Brigitte Kieffer, Pierre Paoletti, Abdel-Mouttalib Ouagazzal. Synaptic zinc contributes to motor and cognitive deficits in 6-hydroxydopamine mouse models of Parkinson’s disease. Neurobi- ology of Disease, Elsevier, 2020, 134, pp.104681. 10.1016/j.nbd.2019.104681. inserm-02438938 HAL Id: inserm-02438938 https://www.hal.inserm.fr/inserm-02438938 Submitted on 14 Jan 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Neurobiology of Disease 134 (2020) 104681 Contents lists available at ScienceDirect Neurobiology of Disease journal homepage: www.elsevier.com/locate/ynbdi Synaptic zinc contributes to motor and cognitive deficits in 6- hydroxydopamine mouse models of Parkinson's disease T ⁎ Joanna Sikoraa,b, Brigitte L. Kiefferc, Pierre Paolettid, Abdel-Mouttalib Ouagazzala, a Laboratoire de Neurosciences Cognitives, Aix-Marseille Univ, CNRS, LNC, UMR 7291, 13331 Marseille, France b Aix-marseille Université, Marseille, France c Douglas Research Center, Department of Psychiatry, McGill University, Montréal, Canada d Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, Paris, France ARTICLE INFO ABSTRACT Keywords: Hyperactivity of glutamatergic corticostrial pathways is recognized as a key pathophysiological mechanism Synaptic zinc contributing to development of PD symptoms and dopaminergic neurotoxicity. Subset of corticostriatal pro- Striatum jection neurons uses Zn2+ as a co-transmitter alongside glutamate, but the role of synaptically released Zn2+ in Motor behavior PD remains unexplored. We used genetically modified mice and pharmacological tools in combination with 6- Recognition memory hydroxydopamine (6-OHDA) lesion models of PD to investigate the contribution of synaptic zinc to disease 6-OHDA associated behavioral deficits and neurodegeneration. Vesicular zinc transporter-3 (ZnT3) knockout mice lacking Mice 2+ fi Parkinson's disease releasable Zn were more resistant to locomotor de cit and memory impairment of nigrostriatal dopamine (DA) denervation compared to wildtype littermates. The loss of striatal dopaminergic fibers was comparable between genotypes, indicating that synaptically released Zn2+ contributes to behavioral deficits but not neu- rotoxic effects of 6-OHDA. To gain further insight into the mechanisms of Zn2+ actions, we used the extracellular Zn2+ chelator CaEDTA and knock-in mice lacking the high affinity Zn2+ inhibition of GluN2A-containing NMDA receptors (GluN2A-NMDARs). Acute chelation of extracellular Zn2+ in the striatum restored locomotor deficit of 6-OHDA lesion, confirming that synaptic Zn2+ suppresses locomotor behavior. Disruption of the Zn2+-GluN2A interaction had, on the other hand, no impact on locomotor deficit or neurotoxic effect of 6-OHDA. Collectively, these findings provide clear evidence for the implication of striatal synaptic Zn2+ in the pathophysiology of PD. They unveil that synaptic Zn2+ plays predominantly a detrimental role by promoting motor and cognitive deficits caused by nigrostriatal DA denervation, pointing towards new therapeutic interventions. 1. Introduction several factors have been implicated, including mitochondrial dys- function, aberrant protein folding (e.g., α-synuclein misfolding into Parkinson's disease (PD) is the most common neurodegenerative toxic conformation), oxidative stress and neuroinflammation (Fujita movement disorder in the elderly characterized by resting tremor, ri- et al., 2014; Lotharius and Brundin, 2002; Russo et al., 2014). gidity, bradykinesia and gait disturbance. PD patients also experience a Compelling evidence support a role of zinc in PD pathogenesis. In range of non-motor symptoms, including autonomic dysfunction, sleep PD patients, excessive zinc deposits are found in the substantia nigra disturbances, depression, anxiety, and cognitive impairment, which can region and the striatum (Dexter et al., 1991). Accordingly, studies using often appear in the early stages of the disease (Papagno and Trojano, experimental models of PD showed that cytosolic accumulation of labile 2018; Whittington et al., 2006; Zis et al., 2015). The pathological Zn2+ is a component of the pathogenic events leading to DA neuron hallmarks of PD include the loss of dopaminergic neurons in the ni- death (Lee et al., 2009; Sheline et al., 2012; Tamano et al., 2018a, grostriatal system coupled with the presence of Lewy bodies composed 2018b). For instance, intracellular zinc chelation protects dopaminergic predominantly of misfolded α-synuclein protein (α-syn). The clinical neurons against neurotoxic effects of MPTP, 6-OHDA and paraquat symptoms of PD have been largely attributed to depletion of dopamine (Sheline et al., 2012; Tamano et al., 2018a, 2018b). Conversely, sys- (DA) at striatal level and the subsequent dysfunction of cortico-basal temic and intracerebral injections of zinc induce dopaminergic neuro- ganglia-thalamo-cortical circuits (Obeso et al., 2000). The pathogenic degeneration and exacerbate nigrostriatal DA neuron loss induced by pathways leading to neurodegeneration remain poorly understood and different neurotoxins (Hussain and Ali, 2002; Kumar et al., 2012, 2010; ⁎ Corresponding author at: Laboratoire de Neurosciences Cognitives, UMR 7291 (AMU-CNRS), 3 Place V. Hugo, 13331 Marseille, France. E-mail address: [email protected] (A.-M. Ouagazzal). https://doi.org/10.1016/j.nbd.2019.104681 Received 30 August 2019; Received in revised form 5 November 2019; Accepted 19 November 2019 Available online 20 November 2019 0969-9961/ © 2019 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). J. Sikora, et al. Neurobiology of Disease 134 (2020) 104681 Lo et al., 2004; Yang et al., 2016). Further evidence for detrimental role the mechanisms of synaptic zinc actions. of zinc in PD comes from genetic and molecular studies showing that the PD-associated human PARK9 (ATP13A2) gene encode for a cation 2. Materials and methods pump (lysosomal type 5 P-type ATPase) that acts as a transporter for lysosomal sequestration of cytoplasmic Zn2+ (Kong et al., 2014; 2.1. Animals Tsunemi and Krainc, 2014). In vitro, PARK9 deficiency causes an al- teration of intracellular Zn2+ homeostasis that in turn initiates a cas- Eight weeks old C57/BL6J male mice were purchased from Charles cade of deleterious events (mitochondrial dysfunction, oxidative stress River Laboratories (France). ZnT3 knockout (KO) mice were generously and α-syn aggregation) that are all involved in PD pathogenesis (Kong provided by Professor Richard Palmiter (University of Washington, et al., 2014; Tsunemi and Krainc, 2014). Contrasting with the above USA) and maintained in pure BL6J genetic background. GluN2A-H128S findings, several studies reported a neuroprotective action of zinc. Zinc knock-in (KI) mice were generated as described before (Nozaki et al., has been shown to reduce oxidative stress induced by 6-OHDA 2011) and maintained in 70% BL6JX129/SvPass genetic background. (Méndez-Álvarez et al., 2002) and prevents methamphetamine-induced Mice were housed in groups of 3–4 in individually ventilated cages dopaminergic neurotoxicity in vitro (Ajjimaporn et al., 2008, 2005). (Techniplast) and kept in 12 h light/dark cycle (light on at 7:00, off at Zinc supplementation was also demonstrated to confer neuroprotection 19:00) with water and food ad lib. Behavioral testing was performed against rotenone-induced Parkinsonism in rats (Mbiydzenyuy et al., during the light cycle between 09 h00 and 17 h00. All experimental 2018) and extend lifespan in drosophila model of PD (Saini and procedures were conducted with the approval of the French national Schaffner, 2010). In view of these findings, it emerges that zinc may ethics committee (CE071) and in accordance with the EEC (2010/63/ play a contrasting role in PD depending of the etiological factors un- UE) guidelines for care and use of laboratory animals. derlying development of the disease. To date, most published studies relates to the pathogenic role of 2.2. Drugs intracellular Zn2+ dyshomeostasis in PD. In the brain, however, a substantial amount (~10%) of total Zn2+ is packed within synaptic 6-Hydroxydopamine hydrochloride (6-OHDA, Tocris Bioscience), vesicles of a subset of glutamatergic terminals (Frederickson et al., was dissolved in a vehicle solution (0.9% sterile NaCl containing 0.02% 2000; Danscher and Stoltenberg, 2005; Paoletti et al., 2009; Sensi et al., ascorbic acid). The extracellular zinc chelator, EDTA calcium disodium 2011). This pool of vesicular (and chelatable) Zn2+ is particularly salt (CaEDTA, Sigma-Aldrich), was dissolved in 0.9% sterile NaCl. abundant in the forebrain (neocortex, hippocampus, striatum, amyg- dala) where zinc positive neurons form a dense associational